Vibrating rectifier.



J. T. DEMPS'TER. VIBRATING RECTIFIER.

APPLICATION FILED SEPT.17, 1908.

1,019,608. PatentedMar. 5, 1912.

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UNITED STATES PATENT OFFICE.

JOHN THOS. DEMPSTER, OF SCHENECTADY, NEW YORK, ASSIGNOR T0 GENERAL- 7ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

' VIBRATING RECTIFIER.

Specification of Letters Patent. Application filed September 17, 1908.

1,019,608. PatentedMar. 5, 1912.

Serial No. 453,412.

is mounted on two resilient springs, or tongues, 18, 19, which areattached at fixed points on support 20, 21 thus constituting a freelyvibrating magnetic reed. 'The springs18, 19 are insulated from thearmature 17 by means of insulators, such as mica plates 22 and 23.springs 18 and 19 which together we may call the vibrator, are soproportioned that the natural period of vibrationwill be approximatelythe same as that of the frequency of the alternating current in mains 1,2. This may be length or stiffness of the weight of the armature 17. Theim-' portance of this feature has not heretofore been recognized inconnectionwith devices of the general type here illustrated. A permanentmagnet 24 is mounted between the poles of the alternating current magnetand adjacent to the air gap, as indicated, and

To all whom it may concern:

Be it known that I, J OHN T. DEMPsTER, a subject of the King of GreatBritain, residing at Schenectady, county of Schenectady, State of NewYork, have invented certain new and useful Improvements in VibratingRectifiersyof which the following is a specification. j

My invention relates to apparatus for converting alternating currentinto direct current.

The invention comprises a device containing a vibrator carrying a set ofcontacts movable in synchronism with the periodicity of the alternatingcurrent and operative to shaft the connections in such a way as to yielddirect current suitable for use in an external or load circuit.

The accompanying drawing illustrates one embodiment of my invention. Itshows a somewhat diagrammatic perspective view of my device, and adiagram of the connections slte ends of the armature 17. For example, ifthe end of the magnet 24, which is nearest the armature 17, is a northpole, a south 'pole will be induced in the end of the armature 17 whichisv nearest the permanent magnet and a north pole at the opposite end,as indicated in the drawing. Two sets of contacts 25, 25 are mounted oneach side of the springs 18 and 19 and are electrically connected withthe springs. The stationary contacts 5, 6, 7 and 8 cooperate with thecontact-s 25 and 25 and are connected respectively to the conductors 26,27; the stationary contacts .7 and 8 also, cooperating with the contacts25, 25 are connected' respectively to conductors 28, 29. The conductor30 connecting lines 27 and 28 to the so as to permit a variation ofimpressed voltage. The ends of the springs 18, 19 are electricallyconnected with lines 31 and 32 which serve to carry the rectifiedcurrent.

Having now described .the parts and connections of my device, I willproceed to explain its manner of operation.

When the circuit is completed through the alternating current magnet 4,the ends of the pole pieces made north and southpoles; As the armature17 is permanently polarized, it w ll be directed first toward one sideand then toward the other in synchronism with the al- The novel featuresof my invention are pointed out in the accompanying claims.

Lines 1, 2 carry an alternating current, supplied by the generator G.Connected across the alternating current mains is the compensator 3.Before taking up the various connections of my device to thecompensator, it" is pointed out, for the sake of clearness,that-thereare two set-s of connections, one set connecting with analternating current magnet 4; and another set connecting with two pairsof stationary contacts 5, 6 and 7, 8, the purpose of which will behereinafter explained. The U-shaped magnet 4 is connected to one side ofthe compensator by means of conductors 9 and 10, the latter havingincluded in its circuit an adjustable reactance coil 11, the purpose ofwhich will 7 The magnet is connected to the other side of thecompensator by means of conductor 12', which has been shown as makingadjustable contact with the compensator, so as to permit regulation ofthe voltage impressed on the magnet 4. Pole pieces 13, 14 are mountedrespectively on each end of the poles 15, 16 of the magnet, thusconstituting with the rest of the mag net a substantially closedmagnetic circuit with an air gap between the pole pieces. Armature'17,adapted to vibrate between the oppositely disposed, free pole pieces 13,14,

serves to induce a magnetic pole at oppo- 13, 14L will be alternatelyvThe armature 17 and i compensator is made adjustable -this can beeasily.

ternations of the current in the magnet 4. Suppose it is directed towardthe pole piece 13; the contacts 5, 6 will then touch the contacts 25, 25mounted on the vibrator and we may assume that the current will flowfrom conductors 30 and 27 to the contact 6, to contact 25 and fromthence out to the direct current line 31 returning over the line 32 asindicated by the arrows, to contact 5, and conductor 26. When thecurrent in the magnet 4 reverses the armature 17 will be moved to theopposite pole, 14,'and the contacts on the opposite side of the springs18, 19 will now touch the stationary contacts 7, 8. The alternatingcurrentwhich has reversed will flow from conductors 9 and 29 to thestationary contact 8, to the contact 25 on the opposite side of thespring 18 and in the same direction on the other line 31, returning over'line 32, to contact 7 and lines 28 and 30. This cycle will be rapidlyrepeated and in this manner and direct current will flow in the lines 31and 32, where it may serve to charge a storage battery 33 or be used inany desired manner.

As the armature 17 and in" fact the vibrator as a whole has a certaininertia, and

therefore requires a definite interval of time in order to change itsposition, it is important that the reversal of current in thealternating current magnet 4: should occur in advance of the reversal ofthe current in the rest of the system. In this manner the reversal ofthe polarity of the magnet 4 will occur in advance ofthe reversal of thecurrent in conductors '9 and 30 and thereby cause the vibrator to makeand break the circuit near the zero point of the alternating currentwave. I find that this requires a displacement of phase of about ninetyelectrical degrees. This displacement may be given ing either acondenser or a reactance'coil in either circuit as it does not matterwhether the current in one of the two circuits is advanced or retardedso long as the phase displacement is about ninety degrees. However, Iprefer to use a reactance coil as made adjustable. The adjustability isan important feature as under certain conditions, as will be laterpointed out, it is important to break the connections before thealternating current wave. reaches the zero point. It is also'importantthat the movmg contacts making connection between the direct currentlines and the alternating current lines ordinarily should be at openclrcuit a minimum 1nterval of time. For this reason these contacts aresituated in an intermediate position between the fixed points ofsupports 20 and 21 and the freely vibrating end represented by thearmature 17 As the springs 18 and- 19 are flexible, most of the movementwill to the current by includtake place in the portion of the springbetween the points of electrical contact and the oscillating armature17. When the armature 17 is moved toward the pole pieces 13, so as tomake contact at 5 and 6 it can move an appreciable distance toward thepole 14 before the contact at 5 and 6 is broken and after these contactsare broken, only a very short interval of time need elapse beforecontact is again made at 7 and 8. When the device is to be used torectify a current for charging a storage battery, it

is so designed with respect to the posit-ion of the moving contacts,

and the amount ot effective reactance in circuit, that the lines 31, 32are open circuited during the time interval" when the storage batteryvoltage equals or exceeds the line voltage, thus avoiding any dischargeof the battery through the instrument. In this case, the phaserelation'" of the currentenergizing the magnet 1, and the current inconductors 26, 27, 28 and 29 is so regulated by adjusting the reactance11, that the contact with 5, 6 and 7, 8 will be broken, not when thealternating current has become zero, but when its voltage has fallen tothe value of the battery voltage. The contact parts are so adjusted thatcontact is not reestablished until the voltage of the alternatingcurrent again equals the battery voltage.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is,

1. In a rectifier, the combination of a magnet having a substantiallyclosed magnetic circuit and having opposing pole pieces with anintervening air gap, means for causing an alternating magnetic fiux insaid magnet, a magnetic member free to vibrate in the air gap, magnetic'means having a pole adjacent to said member and said gap for exertingupon the said member a magnetizing eflect of constant polarity andcooperating switching contacts actuated by the vibration of said memberfor delivering alternating impulses of current as a succession ofunidirectional impulses.

2. In a mechanical rectifier, the combination of a magnet having asubstantially closed magnetic circuit and having opposing poles with anintervening air gap, means for causing an alternating flux in saidmagnet, a resilient magnetic reed adapted to freely vibrate between thepoles of said magnet in the air gap, a fixed support therefor, magneticmeans adjacent to said member and said gap furnishing a unidirectionalmagnetizing flux and cooperating contacts actuated by the vibration ofsaid member for delivering alternating impulses of current as asuccession of unidirectional impulses. I

3. In a vibrating rectifier, the combination of a magnet energized byalternating curswitching the dimensions of said posed with anintervening air gap, an armature free to vibrate in said gap, aresilient tonguesupport for said armature on one side of the gap, amagnetic member of constant polarity in operative relation with saidarmature on the other side of the gap for exerting upon saidarmature amagnetizing flux in the direction of its length and means actuated bythe vibration of said armature for delivering impulses of alternatingcurrent as rectified current.

4. In a mechanical rectifier, the combination of a U-shaped magnethaving oppositely disposed poles with an intervening air gap, means forcausing an alternating flux in said magnet, an armature of substantiallygap free to vibrate longitudinally between the poles of said magnet, acontrol magnet of constant pomagnetic circuit, means for exciting saidlarity mounted between the legs of the alternating current magnet andhaving a pole adjacent to the armature for impressing thereupon amagnetizing flux in the direction of its length, and means actuated bythe vibration of said armature for delivering impulses of. alternatingcurrent as a succession of unidirectional impulses,

5. The combination of an alternating current source, an electromagnethaving oppositely disposed poles with an air gap but having an otherwisesubstantially closed magnet with an alternating flux in step with thevibrations of the current from said source but displaced in phasetherewith, a vibrator comprising an armature free to vibrate betweensaid poles, resilient tongue supports for said armature insulated fromone another, a magnet of constant polarity opposite said vibrator andadjacent to said gap, exerting an inductive effect upon'said armature,stationary contacts, and contacts mounted on said supports and operatingin conjunction with said fixed contacts by the step with the vibrationsof current from said source, an armature free to vibrate in'the air gap,a resilient tongue carrying the armature, a fixed support for one end ofthe tongue; the vibrating element being proportioned to have a naturalperiod of vibration approximating that of said source,

a magnet of constant polarity adjacent to said gap and said armature,exerting an inductive effect upon said armature, and means actuated bythe vibrations of said armature for delivering impulses of current fromsaid source as unidirectional impulsesc 7. In a mechanical rectifier,the combination of an electromagnet having a magnetic circuitsubstantially closed except for an air gap, a source of alternatingcurrent, means for magnetizing said magnet with a flux alternating instep with the vibrations of current from said source, an armature ofconstant polarity of substantially the dimens'ions of said gap arrangedto vibrate therein, a resilient reed support therefor, the armature andreed having a natural period of vibration approximating that of saidsource, a fixed support for the opposite end of said reed and meansactuated by the vibrations of said armature for delivering impulses ofcurrent from said source as unidirectional impulses.

In witness whereof, I have hereunto set my hand this. 15th day ofSeptember, 1908.

JOHN THOS. DEMPSTEB.

Witnesses:

BENJAMIN B. HULL, MARGARET E. WOOLLEY.

